Contrasting responses of plants and pollinators to woodland disturbance

COULIN, CAROLINA; AIZEN, MARCELO A.; GARIBALDI, LUCAS A.

AUSTRAL ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2019 vol. 44 p. 1040 - 1051

1442-9985

Preserving species diversity is critical to ensure ecosystem functioning; however, different componentsof diversity might respond to human disturbance in different ways. Similarly, trophic levels might haveuncoupled responses to the same disturbance, thus ameliorating or aggravating the persistence of ecological communities.In this study, we analysed how the density, richness and evenness of flowers and pollinators respondto four levels of woodland thinning intensity (0, 30, 50 and 70% of woodland basal area removed) over 2 yearsin three contrasting sites. We found a mismatch in the response of flowers and pollinators to thinning. Flowerdensity and richness had disparate responses, depending on the site and year, while evenness did not changewith thinning. In contrast, pollinator density and richness, but not evenness, consistently increased with thinningamong years and sites. These results suggest that thinning has a great influence on pollinators through changesin abiotic conditions and, perhaps, flower attractiveness rather than through small-scale changes in flower densityand richness. At the site where tree flowers were absent, bee pollinator community composition was impoverished,suggesting that trees provide important floral resources to pollinators. Our findings indicate that disturbancemay diminish local plant abundance and richness, but pollinator abundance and richness are enhancedafter intense thinning at small scales.